PLATE XXIV 

 BRACHIA (PAGE 293) 



FIGURE 1. Brachial supports of Macandrevia cranium Miiller; nearly 

 adult; p,p, points of former attachment to a septum in terebrataliform 

 stage. Enlarged. 



FIGURE 2. Dorsal valve of Terebratulina septentrionalis Couthouy, 

 with cirrated brachia attached ; showing relations of calcareous loop, 

 which is darkly shaded in the drawing. 



FIGURE 3. Dorsal valve of Magellania kerguelenensis Davidson, with 

 cirrated brachia attached ; showing relations of calcareous loop, which is 

 darkly shaded in the drawing. 



TEREBRATALIA OBSOLETA DALL (PAGES 406-408) 



FIGURE 4. Loop in late platidiform stage, with cirrated margin of 

 lophophore attached. X 15. 



FIGURE 5. Side view of lower half of preceding ; showing cirrated 

 edge of lophophore passing from the descending branch of loop to sep- 

 tum, and over ascending branch. X 15. 



FIGURE 6. Dorsal view of adult shell. Natural size. 



FIGURE 7. Exterior of ventral valve. Natural size. 



FIGURE 8. Profile ; showing relative convexity of valves. Natural 

 size. 



FIGURE 9. Front view. Natural size. 



FIGURE 10. Early larval brachiopod ; interior of dorsal valve ; show- 

 ing the incomplete circlet of tentacles or cirri, visceral mass, and some of 

 the muscles ; ti, li', first tentacles developed ; ti, te', second pair of ten- 

 tacles ; te, tz', third pair of tentacles; U, U', last pair; te, new tentacle 

 just growing on one side of median line; m, mouth ; ds, dental sockets; 

 did, diductor muscles ; ad, adductor muscles. X 90. 



Figures 10, 11, 12, are drawn from specimens which had been dried 

 and afterward expanded by soaking in water, and then stained and pre- 

 pared for mounting. The original proportions and relations of parts 

 may be therefore somewhat altered. 



FIGURE 11. Gwyniform stage; showing complete circle of cirri; ps, 

 pallial sinus ; se, setse in edge of shrunken mantle. X 60. 



FIGURE 12. Cistelliform stage ; showing deflection of growing cir- 

 rated edge of lophophore by dorsal septum (s) ; m, mouth ; ad, adductor 

 muscles ; did, diductor muscles ; ds, dental sockets. X 60. 



